The move reflects the growing importance of software to cars. While not as momentous as its introduction of the Prius in 1997—the first mass-produced hybrid vehicle—Toyota Motor Corp quietly took another bold, industry-leading step toward technological innovation last month.

The world’s largest automaker ponied up a one-time fee—believed to be $20 million—and became the eighth full member of a consortium that most people do not associate with the auto industry at all.

It’s called the Open Invention Network, and its other members are Google, IBM, Red Hat, NEC, Philips, Sony, and SUSE (a unit of Britain’s Micro Focus). ...Formed in 2005, OIN’s mission is to protect and encourage the collaborative development and use of open-source software, like the Linux operating system, which can be freely copied, altered, and distributed, and which no one person or company owns. OIN pursues a variety of strategies aimed at protecting the users and developers of such software against the threat of patent suits by proprietary software manufacturers, like Microsoft and Apple. Such suits, if successful, could deny users the freedoms that make open-source software desirable.